The Firebird II was the second of the three gas-turbine powered experimental Firebirds developed by General Motors during the 1950s in its search for alternative means of automobile propulsion. It made its public debut at the GM Motorama  of 1956 in New York City’s Waldorf-Astoria Hotel as a revolutionary form of family transportation destined for travel along the "Safety Autoway" of the future.

The Firebird II was designed by GM Styling under the direction of Harley Earl. His vision for the Firebird II was that of a comfortable, four-seat family car. There were two identical bodies built for the Firebird II, one made of titanium and one made of fiberglass. The use of titanium was a significant design feature as it was the first time this lightweight metal was used in the construction of a motorcar. The titanium body was left unpainted at Harley Earl’s insistence and was brush-finished to a satin luster.

The exterior design of the Firebird II was aerodynamic from the low tapered nose to the dorsal fin deck. Fuel tanks were suspended from the rear fender on either side of the car. A transparent canopy allowed for 360 degree visibility and had sections that automatically lifted up from the doors to admit passengers when a magnetic key was inserted into a slot on the body panel. In keeping with the theme of family transportation, the Firebird II had a luggage compartment that held eight pieces of specially styled lightweight fitted luggage. The compartment was just below the rear deck and rose to waist height for ease of use with the flip of a switch.

The Firebird II and engineered for use along the electronic highway of the future. Its communications system allowed the driver to contact an operator along this automated highway who would take control of the vehicle and guide it to its destination thus allowing for a more pleasant and less stressful traveling experience. The interior of the Firebird II featured four individually adjustable, reclining lounge seats for maximum passenger comfort and snack tables for use during automated travel.

General Motors Research Laboratories developed the engine and chassis for the Firebird II under the guidance of Research Vice President Dr. Lawrence R. Hafstad. The new Whirlfire GT-304 gas turbine engine powered the vehicle tackled the fuel consumption, high heat loss, and engine noise problems of its predecessor, the GT-302, that drove the Firebird I. As such, this engine was much more efficient and provided a big step forward in the development of gas turbine propulsion.

The second prototype, the Firebird II in 1956, was a more practical design: a four-seat, family car. It is a low and wide design with a large dual air intakes in the front, a high bubble canopy top, and a vertical tail fin. Its exterior bodywork was made entirely of titanium. The engine output was 200 hp (150 kW), and to solve the exhaust heat problem it was fed through a regenerative system, which allowed the entire engine to operate at nearly 1,000 °F (538 °C) cooler, and also power the accessories. Another innovation on the car was the first use of four wheel disc brakes, with a fully independent suspension, as well as a sophisticated guidance system which was intended to be used with "the highway of the future", where an electrical wire would be embedded into a roadway to send signals that would help guide future cars and avoid accidents.

source: Wikipedia